For radar-based level measurement all known methods may be employed which permit distances to be measured by means of reflected microwaves, the best-known examples of which are pulsed radar and frequency modulated continuous wave radar (FMCW radar). In pulsed radar short microwave transmission pulses are emitted periodically which are reflected by the object being measured and re-received as an echo signal after a transit time depending on the distance involved. The received signal amplitude versus time function constitutes an echo function or echo profile. Every value of this echo function corresponds to the amplitude of an echo due to reflection at a certain distance from the antenna. In FMCW radar a continuous microwave is emitted which is periodically linearly frequency-modulated, for example, according to a saw-tooth function. The frequency of each received echo signal thus exhibits with respect to the instantaneous frequency which the transmission signal has at the time of reception, a difference in frequency which depends on the transit time of the echo signal. The difference between the frequency of the transmission signal and that of the reception signal which may be obtained by mixing both signals and evaluating the Fourier spectrum of the mixed signal, thus corresponds to the distance of the reflecting surface of the object away from the antenna, and the level of the frequency characteristic corresponds to the magnitude of the echo amplitude. This Fourier spectrum, therefore, constitutes the echo function in this case. In prior art the entirety of the echo function obtained in the course of a measurement cycle is stored and then the stored echo function is evaluated according to a given program by a computer to establish the useful echo and to determine the transit time of the useful echo. Storing the echo function in this case is preferably done in digitized form by the echo function being periodically sampled, each sampled value being converted by an analog-to-digital converter into a digital code group and the digital code groups being written into a RAM of the computer.